Preparation of lubricant additive and lubricant composition containing same



atent 3,042,613 Patented July 3, 1962 Free 3,042,613 PREPARATION OF LUBRICANT ADDITIVE AND LUBRICANT COMPOSITION CONTAINING SAME Norman E. Lemmon, Hammond, and Albert R. Sahel,

Munster, Ind., assignors to Standard Oil Company, Cliicago, 111., a corporation of Indiana No Drawing. Filed Nov. 20, 1958, Ser. No. 775,118 11 Claims. (Cl. 25232.7)

This invention relates to improvements in the preparation of lubricant additives, and more particularly pertains to the preparation of neutralized phosphorus sulfide-hydrocarbon reaction products having a high alkaline earth metal to phosphorus ratio which is compatible with fatty acid polymers with substantially no viscosity increase.

Many modern automobile engines are designed with hydraulic valve-lifters for smoother and more eflicient engine operation. In the operation of hydraulic valvelifters, the lifter rise on the cam shaft converting the rotary motion of the cam into a reciprocating motion, which in turn opens and closes the valves. The bottom of the valve-lifter is known as the cam follower. The hydraulic part of the valve-lifter functions by means of a plunger on the inside of the valve lifter barrel, together with a ball-check and a spring. To obtain higher efficiency and greater horsepower, larger valves, higher valve spring pressures and camshafts which produce more rapid valve opening and closing are employed. In the operation of such engines, greatly increased pressures are encountered where the camshaft lobes come into contact with the faces of the valve-lifters resulting in excessive and severe cam and lifter wear as well as pitting of the cam followers. This wear and/ or pitting cannot be adequately inhibited by most present-day internal combustion engine crank-case lubricants. Surprisingly, the type of anti-wear properties which will inhibit piston ring and/or cylinder wear are not necessarily the same as the anti-wear properties necessary to prevent cam and lifter wear and/ or pitting; hence many lubricants which are etfective in inhibiting ring and cylinder wear are ineffective in preventing cam and lifter wear. A further complicating factor in this problem is caused by the materials used in making the camshaft and valve-lifters since different metals and metal combinations are used for this purpose in the various engines. Camshaft and valve-lifter combinations of different metals create different requirements on the lubricant in that certain types of anti-wear additives may be effective with some cam-lifter metal combinations but ineffective with other metal combinations. Furthermore, because of the small clearances between the plunger and the barrel of hydraulic valve-lifters, extremely small amounts of deposits such as varnish and/ or rusting may cause sticking of the valve-lifter. for good engine operation to provide a lubricant which will, in addition to inhibit Wear and/ or pitting also inhibit the formation of varnish and/or rusting in the valve-lifter.

Such cam follower pitting and/ or wear, and the sticking of hydraulic valve lifters can be effectively inhibited by using lubricating oils containing small amounts of an alkaline earth neutralized reaction product of a phosphorus sulfide and a hydrocarbon in combination with a fatty acid polymer such as polymeric linoleic acids, e.-g. linoleic and dimers, and mixtures of polymeric fatty acids; such as is described in US. 2,833,713 issued to N. E. Lemmon et al. May 6, 1958. While the additive combination of the Lemmon et al. patent is effective when used with substantially neutral alkaline earthcontaining phosphorus sulfide-hydrocarbon reaction Hence, it is essential products, decreased effectiveness is exhibited when the polymeric fatty acid is used in combination with alkaline earth-containing phosphorus sulfidehydrocarbon reaction products of high alkalinity.

It is an object of the present invention to provide a method of preparing an alkaline earth-containing neutralized reaction product of a phosphorus sulfide and a hydrocarbon having a high alkaline earth-to'phosphorus ratio which is compatible with polymeric fatty acids with substantially no viscosity increase. It is another object of the invention to provide a lubricant composition containing an alkaline earthcontaining neutralized phosphorus sulfide-hydrocarbon reaction product so prepared and a polymer fatty acid. Other objects and advantages of the invention will become apparent from the following description thereof.

In accordance with the present invention, a fluid, free flowing lubricating oil additive concentrate consisting essentially of a neutralized alkaline earth-containing reaction product of a phosphorus sulfide and a hydrocarbon and a polymeric high molecular weight carboxylic acid, hereinafter defined, in the ratio of from about 20:1 to about 20:2 respectively is prepared by the process comprising reacting a phosphorus sulfide with a hydrocarbon, reacting the resultant reaction product with a sufiicient amount of a basic alkaline earth compound to give an alkaline earth-containing reaction product having an excess alkalinity of at least about 2 milligrams NaOH per gram of product, and usually from about 2 to about 20 milligrams NaOH per gram of product, treating the alkaline reaction product with CO at a temperature of from about F. to about 350 F. for a time sufiicient to reduce the alkalinity of the product to a value of about zero milligram NaOH per gram of product, and subsequently incorporating a polymeric high molecular weight fatty acid, in the above mentioned ratio, at a temperature of from about 100 F. to about 300 F., preferably from about F. to about 180 F. The alkalinity is determined by mixing five grams of the sample with ccs. of 95% ethyl alcohol and 200 ccs. naphtha and titrating with sodium hydroxide using phenolphthalein indicator. While not essential, it is preferred to conduct the C0 treatment in the presence of from about 0.1% to about 5% of water based on the alkaline additive.

In the preparation of the phosphorus sulfide-hydrocarbon reaction products, the hydrocarbon is reacted with a phosphorus sulfide, such as P 8 P 8 P 8 or other phosphorus sulfides, and preferably phosphorus pentasulfide, P 5 as described in detail in US. 2,316,- 808, 2,316,082, and 2,316,088, each issued to Loane et al. on April 6, 1943.

The hydrocarbon constituent of this reaction is suitably a normally non-gaseous hydrocarbon having a molecular weight of at least about 150. While the by drocarbon constituent of this reaction can be any of the type hereinafter described, it is preferably a mono-olefin hydrocarbon polymer resulting from the polymerization of low molecular weight mono-olefinic hydrocarbons or isomono-olefinic hydrocarbons, such as propylene, butylcues, and amylenes or the copolymers obtained by the polymerization of hydrocarbon mixtures containing isomono-olefins and mono-olefins or mixtures of olefins in the presence of a catalyst, such as sulfuric acid, phosphoric acid, boron fluoride, aluminum chloride or other similar halide catalysts of the Friedel-Crafts type.

The polymers employed are preferably mono-olefin polymers or mixtures of mono-olefin polymers and isomono-olefin polymers having molecular weights ranging from about 150 to about 50,000 or more, and preferably from about 300 to about 10,000. Such polymers can be et al. April 6, 1943.

obtained, for example, by the polymerization in the liquid phase of a hydrocarbon mixture containing mono-olefins and isomono-olefins such as butylene and isobutylene at a temperature of from about -80 F. to about 100 F. in the presence of a metal halide catalyst of the Friedel- Crafts types such as, for example, boron fluoride, aluminum chloride, and the like. In the preparation of these polymers we may employ, for example, a hydrocarbon mixture containing isobutylene, butylenes and butanes recovered from petrolum gases, especially those gases produced in the cracking of petroleum oils in the manufac ture of gasoline.

Essentially paraflinic hydrocarbons such as bright stock residuums, lubricating oil distillates, petrolatums, or paraffin waxes, may be used. There can also be employed the condensation products of any of the foregoing hydrocarbons, usually through first halogenating the hydrocarbons, with aromatic hydrocarbons in the presence of anhydrous inorganic halides, such as aluminum chloride, zinc chloride, boron fluoride, and the like.

Other preferred olefins suitable for the preparation of the herein described phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule of which from about 13 carbon atoms to about 18 carbon atoms, and preferably at least 15 carbon atoms are in a long chain. Such olefins can be obtained by the dehydrogenation of paraffins, such as by the cracking of paraflin waxes or by the dehalogenation of alkyl halides, preferably long chain alkyl halides, particularly halogenated parafiin waxes.

Also contemplated within the scope of the present invention are the reaction products of a phosphorus sulfide with an aromatic hydrocarbon, such as for example, benzene, naphthalene, toluene, xylene, diphenyl and the like or with an alkylated aromatic hydrocarbon, such as for example, benzene having an alkyl substituent having at least four carbon atoms, and preferably at least eight carbon atoms, such as long chain paraffin wax.

The phosphorus sulfide-hydrocarbon reaction product is prepared by reacting the phosphorus sulfide, e.g. P 8 with the hydrocarbon at a temperature of from about 150 F. to about 600 F., preferably from about 300 F. to about 500 F., using from 1% to about 50%, preferably from about 5% to about 25% of phosphorus sulfide; the reaction is carried out in from about one to about ten hours. It is preferable to use an amount of the phosphorus sulfide that will completely react with the hydrocarbon so that no further purification is necessary; however, an excess of the phosphorus sulfide can be used, and the unreacted material separated by filtration. The reaction, if desired, can be carried out in the presence of a sulfurizing agent such as sulfur or a halide of sulfur as described in U.S. 2,316,087, issued to J. W. Gaynor, It is advantageous to maintain a non-oxidizing atmosphere, for example an atmosphere of nitrogen, in the reaction vessel. The reaction product obtained is then hydrolyzed at a temperature of from about 200 F. to about 500 F., preferably at a temperature of about 300 -F.-400 F. by suitable means, such as for example, by introducing steam through the reaction mass. The hydrolyzed product, containing inorganic phosphorus acids formed during the hydrolysis, can be used as such in the subsequent neutralization stage; or it can be substantially freed of the inorganic phosphorus acids by contacting with an adsorbent material such as Attapulgus clay, fullers earth and the like at a temperature of 100 F.500 -F. as fully described and claimed in U.S. 2,688,612, issued to R. Watson September 7, 1954, or by extraction with phenol or an alkanol of 1 to 5 carbon atoms in admixture with water as described and claimed in Lemmon et al. U.S. Patent No. 2,843,579, issued July 15, 1958.

' The hydrolyzed reaction product is reacted with a basic alkaline earth compound, such as an oxide or hydroxide of barium, calcium, strontium or magnesium to obtain in an oil, preferably an oil similar to the lubricating oil in which the additive is to be used. The total amount of the basic alkaline earth compound present in the slurry should be from about 3 to about 15 parts per part of the phosphorus present in the phosphorus sulfide-hydrocarbon reaction product reactant. Reaction with the basic alkaline earth compound is carried out at a temperature of from about 100 F. to about 500 F., preferably from about 120 F., to about 350. F. The reaction is preflysts.

erably, but not necessarily, carried out in the presence of a mixture of water and a low molecular weight alkanol, of 1 to 4 carbon atoms, e.g. methanol as described and claimed in U.S. 2,806,022 issued to Sabol September 10, 1957.

The hydrolyzed phosphorus sulfide-hydrocarbon reaction product after reaction with the basic alkaline earth compound normally contains an alkalinity of from about 2 to about 20 milligrams NaOH per gram of product. The product so obtained can be used in the formulation of lubricating oil compositions in combination with many other additives. However, when the above hydrolyzed product is to be used in lubricating oil compositions in combination with a polymeric high molecular weight fatty acid undersirable gelling and/or thickening of the composition is encountered. In accordance with the present invention, the alkaline earth containing hydrolyzed phosphorus sulfide-hydrocarbon reaction above described, prior to being incorporated in the lubricant composition in combination with the polymeric fatty acid, is treated with CO at a temperature of from about F. to about 300 F. for a period of time sufficient to reduce the alkalinity of the alkaline earth-containing hydrolyzed phosphorus sulfide-hydrocarbon reaction product to a value of about zero milligrams NaOH per gram of product, by the above described procedure for measuring free alkalinity.

The polymeric carboxylic acid used is a polymeric high molecular weight unsaturated carboxylic acid having a molecular weight of at least about 300 and preferably 9 they may have a lesser or greater number of carbon atoms. Examples of the neutral fatty acids are those such as linoleic, linolenic, ricinoleic (which upon heating forms linoleic acid), linoleaidic, elaidolinolenic, eleostearic, arachidonic, eicosatrienaic, cetoleic, docosatrienoic and the like. The free fatty acids can be polymerized either thermally or with the assistance of cata- A method of thermally polymerizing free fatty acids (see U.S. 2,482,761) consists of hydrolyzing a fat or an oil, adding a small portion of water, and heating in a pressure vessel until substantially all of the diand tri-unsaturated fatty acids present polymerize. The resultant product is then heated at a reduced pressure to distil off vaporizable constituents, leaving behind the polymerized unsaturated fatty acids. The polymerization reaction is carried out at a temperature of about 300 to 360 C. for about three to eight hours at a pressure varying between 75 and 500 p.s.i.g. The polymerization product may consist of monomers, dimers, trimers, and higher polymers of the unsaturated fatty acids. The various fats or oils which may be hydrolyzed to produce the free fatty acids used in the above thermal polymerization are those such as sardine oil, linseed oil, soybean oil, castor oil, peanut oil, palm oil, olive oil, cottonseed oil, sunflower seed oil, and the like.

Another method of preparing the polymerized fatty acids consists of subjecting fats and oils such as have been listed supra (without previous hydrolysis) to a thermal or catalytic polymerization to cause polymerization of the esters of the unsaturated carboxylic acids to the dimers, trimers, and higher polymerization products thereof, followed by hydrolysis to yield the corresponding polymers of the acids. A large source of the polymerized unsaturated fatty acids are those residual acids obtained by methanolysis (see US. 2,450,940) of the semi-drying or drying type oils such as castor oil, soybean oil and others listed supra, polymerizing the methyl esters, removing unpolymerized compounds, saponifying the residual esters and freeing polymerized acids therefrom. The products of catalytic polymerization of semidrying oils such as the BF;, polymerization products of soybean oil, cottonseed oil, or the like, also produce polymers suitable for use in the invention.

A useful, commercially available dimeric carboxylic acid is commercially available from Emery Industries, Inc. under the tradename Emery 955-Dimer Acid. Since the commercial product is produced by dimerization of linoleic acid, it is usually referred to as dilinoleic acid. The commercial acid having a molecular weight of about 600, typically contains about 85% of the dilinoleic acid, about 12% of trilinoleic acid and about 3% of monomeric acid.

Typical specifications for the commercial product are as follows:

Iodine value 80-95 Acid value 180-192 Saponification value 185-195 Unsaponifiable 2.0% max. Color, Gardner. 12 max. Neutralization equivalent 290-310 Refractive index at 25 C 1.4919 Specific gravity at 155 C./15.5 C 0.95 Flash point, F 530 Fire point, F 600 Viscosity at 25 C. (Gardner Holdt) Z4 Viscosity at 25 C., centistokes 10,000 Viscosity at 100 C., centistokes 100 Another suitable polymeric fatty acid material is a mixture of polymerized fatty acids predominating in trilinoleic acid. A particularly satisfactory acid is commercially available from the W. C. Hardesty Company under the trade name of D-SO Acid. Another suitable product is marketed by Rohm & Haas Company under the trade name VR-l Acids. Such acids may be produced as by-product still-residues in the manufacture of sebacic acid by the distillation of castor oil in the presence of caustic. A method of obtaining such by-product stillresidues in the preparation of sebacic acid is described in US. 2,470,849 issued to W. E. Hanson May 24, 1949. The mixture of high molecular weight unsaturated carboxylic acids comprises monomers, dimers, trimers and higher polymers in the ratio of from about 45% to about 55 of a monomers and dimers fraction having a molecular weight in the range of from about 300 to 600, and from about 45% to about 55% of a trimers and higher polymer fraction having a molecular weight in excess of 600. The carboxylic acid'polymers result in part from a thermal polymerization of fatty acid type constituents of the castor oil, and in part from other reactions, such as the inter-molecular esterification, of such acid to form high molecular weight products. The acid mixture, which is mainly a mixture of polymeric long chain polybasic carboxylic acids, is further charactenzed by the following specifications:

Acid No.-- to 164 Saponification No.- to 186 Free fatty acids-75 to 82% Iodine value44 to 55 The preparation of the lubricating oil additive in accordance with the herein described invention is demon strated'by the following example which is given by way of illustration and is not to be construed as a limitation of the invention.

A. PREPARATION OF THE HYDROLYZED PHOS- PHORUS SULFIDE-HYDROCARBON REACTION PRODUCT A polybutene having a mean molecular weight of about 780-800 was reacted with 15.5% (wt.) P 8 at about 450 F. for about 5.5 hours, the reaction product hydrolyzed by steaming at 300 F. for 5.5 hours and the resultant hydrolyzed product diluted with an SAB'SW petroleum motor oil base to give a product having a phosphorus content of 2.71% (eqv. to 1 mole phosphorus). This hydrolyzed product will be referred to as Product A. Portions of Product A were processed as follows:

E. TREATMENT OF PRODUCT A 3-1: Product A, 50% diluted with an SAE-SW mineral oil base, was stirred with 1.5 mols of 13210 per mol of phosphorus at about 75 F. to obtain thorough mixing, and to the mixture were added 0.8 mol water per mol of BaO and 7 mols of methanol per mol of BaO, and the entire mixture heated under reflux conditions for 3 hours at 158-l60 F. The refluxed mixture was then heated to about 400 F. to remove water and methanol and then clay filtered. The recovered filtrate, a barium containing reaction product of the P S -polybutene, had an alkalinity of about 14 milligrams NaOH per gram of product, a barium content of 7.9% and a phosphorus content of 1.3%.

13-2: Product A was treated as in B-l with 1.5 mols BaO per mol of phosphorus to give a product having an alkalinity of about 13.6 milligrams NaOH per gram of product.

B-3: Product A was treated as in B-l but with 1.2 mols 133.0 per mol of phosphorus to give a product having an alkalinity of about 6.35 milligrams NaOH per gram of product.

B-4: Product A was treated as in 13-1 but with 1.15 mols BaO per mol of phosphorus to give a product having an alkalinity of about 2.45 milligrams NaOH per gram of product, a barium content of 6.8% and phosphorus content of 1.23%.

Similarly, reaction products of the phosphorus sulfide and the polybutene, or other hydrocarbons containing other alkaline earth metals can be obtained. While it is preferable to conduct the reaction with the basic alkaline earth compound, e.g. BaO, in the presence of an alkanol, e.g. methanol, and water, as shown in the above examples, this is not essential and the reaction can be carried out in the absence of the alkanol and water.

When such alkaline reaction products are employed in lubricating oils in combination with the polymeric fatty acids, thickening or gelling of the product results. Such thickening or gelling is avoided by blowing the alkaline product with CO at a temperature of 180 F. to 350 F. until. the alkalinity is reduced to a value of about zero. The treatment of CO is preferably, although not necessarily, carried out in the presence of 0.1 to about 5% Water. The treatment of the alkaline product: with CO renders the former essentially unreactive with the polymerized fatty acid in ratios of from about 20:1 to about 20:2 respectively, so at such ratios the combination of additives is fluid.

The effectiveness of the present invention is illustrated by the datain Table I which show the effect of CO treating of various alkaline barium-containing reaction products of P 8 and a polybutene, e.g. products B1, B-2, B-3 and B-4, and the subsequent addition of a polymerized fatty acid, e.g. the product D-SO, supra, which is essentially a mixture of high molecular weight unsaturated fatty acids comprising monomers, dimers, trimers, and higher polymers in the ratio of from about 45% to about 55% of a monomers and dimers fraction having a molecular weight in the range of from about 300 to about 600, and from about 55% to about 45% of a trimers and higher polymers fraction having a molecular weight in excess of about 600, and an essentially dimerized linoleic acid referred to as Dimer Acid and comprising 85% of a dilineoleic acid, about 12% of trilinoleic acid and about 3% linoleic acid.

tained with products prepared in accordance with the present invention.

1 In the accelerated rust test a composition consisting of 1% of the mixed identified additives, 29% of a solvent extracted SAE- mineral 011 base and 70% naphtha is used.

Table I O0; Treatment Ratio Poly. Acid Reaction Con- Perof B ditions Product Alkalincent Gram Product Visc.

ity H1O Used to Poly. at RT 1 Temp, Hrs Alkalin- Acid Grams Grams Temp, Hrs

F. ity a Dimer 13-50 F.

14. 3 l4. 3 300 0. 3 S 14. 3 20 300 0. 3 0. 0 300 0. 3 F 14. 3 20 300 1. 0 0.0 300 0.3 F 13. 6 20 13. 6 180 1.0 S 13. 6 20 300 1.0 0.0 180 1.0 F 6.35 20 6.35 180 1.0 S 6. 20 6.35 180 1.0 S 6. 35 20 300 .75 0. 0 300 l. 5 F 6.35 20 300 .30 0.0 180 1.0 F 2. 20 2. 45 180 1. 0 3-3 2. 45 20 300 0. 5 0.0 180 1.0 F 2. 45 20 400 1.0 0.0 180 0.1 F 2. 45 20 300 1. 0 0.0 180 0. 1 F

1 Vise. at RT:

S=Solld at RT. F=Fluld at RT.

SI =Merely flows at RT. 1 Milligrams NaOH per gram product.

As shown by the above data, alkaline earth-containing phosphorus sulfide hydrocarbon reaction products treated with carbon dioxide in accordance with the present invention when admixed with polymeric high molecular weight fatty acids are fluid at room temperatures, whereas in the absence of such carbon dioxide treatment the mixtures are solid at room temperatures.

The combination of the alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product prepared in accordance with the present invention, and the polymeric high molecular weight polybasic carboxylic acid, herein defined are useful additives for hydrocarbon lubricating oil compositions, for example, lubricating oils for internal combustion engines. When used in lubricating oil composition for internal combustion engines, from about 1 to about 20% of the alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product and from about 0.1 to about 1.0% of the polymeric acid are used. Such lubricants can contain small amounts of other additives usually employed in such compositions, such as for example metal salts of dialkyldithiophosphates, e.g. zinc dialkyldithiophosphate, V.I. improvers, e.g. high molecular Weight polybutenes, methacrylate polymers, etc., pour point depressors, e.g. condensation products of chlorinated paraflin wax and naphthalene, anti-Wear agents, etc.

Hydrocarbon oil compositions containing the combination of the carbon dioxide-treated alkaline earth-containing phosphorus sulfide reaction product, the polymeric high molecular weight polybasic carboxylic acid and a small amount of water exhibit improved rust preventive properties. The amount of water in the finished composition is preferably in the range of from about 0.1% to 1.0%; the water may be present in the carbon dioxide treated product when such treatment is conducted in the presence of water, or the water can be added after the carbon dioxide treatment. The data in Table II demonstrate the improvement in rust prevention properties 0b- In the above accelerated rust test, a 5 x 7 cm. steel panel is cleaned by sand blasting and the cleaned panel dipped in the above blend of oil, naphtha and additive for one minute. The dipped panel is allowed to drain at room temperature for 30 minutes and then immersed in distilled water at F. The panel is considered to fail when about 0.1% of the total area develops rust spots or stains.

Percentages given herein and in the appended claims are weight percentages unless otherwise stated.

Although the present invention has been described with reference to specific preferred embodiments thereof, the invention is not to be considered as limited thereto, but includes within its scope such modifications and variations as come within the spirit of the appended claims.

Weclaim:

1. In the process of preparing an additive combination for hydrocarbon lubricating oils, which additive combination consists essentially of a polymeric high molecular Weight unsaturated polybasic carboxylic acid and an alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product obtained by reacting a normally nongaseous hydrocarbon with a phosphorus sulfide at a temperature of from about F. to about 600 F., hydrolyzing the resultant phosphorus sulfide-hydrocarbon reaction product at a temperature of from about 200 F. to about 500 F and reacting said hydrolyzed reaction prodnot with sumcient amount of a basic alkaline earth compound to obtain a basic alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product having an excess alkalinity of at least 2 milligrams NaOI-Iper gram of product, the improvement of making said basic alkaline earth-reacted hydrolyzed reaction product suitable for admixing With a polymeric high molecular Weight unsaturated polybasic carboxylic acid in the ratio of from about 20:1 to about 20:2, respectively, in a hydrocarbon lubricating oil without thickening said basic admixture, which improvement comprises blowing said alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product with carbon dioxide at a temperature of from about 100 F. to about 350 F. for a time suflicient to reduce the alkalinity of said alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product to a value of about zero milligram NaOH per gram of product prior to admixture with said polymeric high molecular weight unsaturated polybasic carboxylic acid.

2. The process of claim 1 in which the polymeric high molecular weight unsaturated carboxylic acid is dilinoleic acid.

3. The process of claim 1 in which the polymeric high molecular Weight unsaturated carboxylic acid is a mixture comprising essentially monomers, dimers, trimers and higher fatty acid polymers in the ratio of from about 45% to about 55% of a monomer and dimer fraction having a molecular weight in the range of from about 300 to about 600, and from about 55% to about 45 of a trimer and higher polymer fraction having a molecular weight in excess of about 600.

4. The process of claim 1 in which the non-gaseous hydrocarbon is an olefin hydrocarbon having a molecular weight of at least about 150.

5. The process of claim 1 in which the non-gaseous hydrocarbon is a polybutene.

6. The process of claim 1 in which the basic alkaline earth compound is BaO.

7. A normally fluid lubricant composition comprising a major proportion of a hydrocarbon lubricating oil, from about 0.05% to about 1.0% of a polymeric high molecular weight unsaturated polybasic carboxylic acid and from about 1% to about 20% of an alkaline earth-containing phosphorus sulfide-hydrocarbon reaction product obtained by the method of claim 1.

8. A normally fluid lubricant composition having rust preventive properties comprising a major proportion of a hydrocarbon lubricating oil from about 0.05% to about 1.0% of a polymeric high molecular weight unsaturated polybasic carboxylic acid from about 0.1% to about 1.0% water and from about 1% to about 20% of an alkaline earth-containing phosphorus sulfide-hydrocarbon reac tion product obtained by the method of claim 1.

9. 'In the process of preparing an additive combination for hydrocarbon lubricating oils, which additive combination consists essentially of a polymeric high molecular weight unsaturated polybasic carboxylic acid and bariumcontaining phosphorus sulfide-polybutene reaction product obtained by reacting a polybutene with P 8 at a temperature of from about F. to about 600 F., hydrolyzing the resultant P S -polybutene reaction product at a temperature of from about 200 F. to about 500 F., and reacting said hydrolyzed reaction product with sufficient barium oxide to obtain a basic barium-containing P S -polybutene reaction product having an excess alkalinity of from about 2 to about 20 milligrams NaOH per gram of product, the improvement for making said barium oxide-reacted hydrolyzed reaction product suitable for admixing with a polymeric high molecular weight unsaturated polybasic carboxylic acid in the ratio of from about 20:1 to about 20:2, respectively, in a hydrocarbon lubrieating oil Without thickening said admixture, which improvement comprises blowing said barium-containing P S -polybutene reaction product with carbon. dioxide at a temperature of from about 180 F. to about 350 F. for a time sufiicient to reduce the alkalinity of said barium containingP s -polybutene reaction product to a value of about zero milligram N aOH per gram of product prior to admixture with said polymeric high molecular weight unsaturated polybasic carboxylic acid.

10. The process of claim 9 in which the blowing With carbon dioxide is carried out in the presence of from about 0.1% to about 5% Water based on the barium oxide.

11. A normally fluid lubricant composition comprising a major proportion of a hydrocarbon lubricating oil, from about 0.05 to about 1.0% of a polymeric high molecular weight unsaturated polybasic carboxylic acid and from about 1% to about 20% of an alkaline earthcontaining phosphorus sulfide-hydrocarbon reaction product obtained by the method of claim 10.

References Cited in the file of this patent UNITED STATES PATENTS 2,762,774 Popkin Sept. 11, 1956 2,767,209 Assefi et a1. Oct. 16, 1956 2,833,713 Lemmon et al. May 6, 1958 2,841,552 Richardson et a1. July 1, 1958 2,906,709 Lemmon et a1. Sept. 29, 1959 i FOREIGN PATENTS 785,196 Great Britain Oct. 23, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,042, 613 July 3, 1962 Norman E. Lemmon et a1 It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, lines 50 and 51 for "U.S. 2,316,808" read U.S. 2,316,080 column 3, line 10, for "petrolum" read petroleum column 4, line 31 for "undersirable" read undesirable column 6, line 40, for "7.9% read 7.98%

Signed and sealed this 5th day of March 1963.

SEAL) ESTON G. JOHNSON DAVID L. LADD testing Officer Commissioner of Patents 

1. IN THE PROCESS OF PREPARING AN ADDITIVE COMBINATION FOR HYDROCARBON LUBRICATING OILS, WHICH ADDITIVE COMBINATION CONSISTS ESSENTIALLY OF A POLYMERIC HIGH MOLECULAR WEIGHT UNSATURATED POLYBASIC CARBOXYLIC ACID AND AN ALKALINE EARTH-CONTAINING PHOSPHROUS SULFIDE-HYDROCARBON REACTION PRODUCT OBTAINED BY REACTING A NORMALLT NONGASEOUS HYDROCARBON WITH A PHOSPHRUS SULFIDE AT A TEMPERATURE OF FROM ABOUT 150*F. TO ABOUT 600*F. HYDROLYZING THE RESULTANT PHOSPHORUS SULFIDE-HYDROCARBON REACTION PRODUCTION AT A TEMPERATURE OF FROM ABOUT 200*F. TO ABOUT 500*F., AND REACTING SAID HYDROLYZED REACTION PRODUCT WITH SUFFICIENT AMOUNT OF A BASIC ALKALINE EARTH COMPOUND TO OBTAIN A BASIC ALKALINE EARTH-CONTAINING PHOSPHORUS SULFIDE-HYDROCARBON REACTION PRODUCT HAVING AN EXCESS ALKALINITY OF AT LEAST 2 MILLIGRAMS NAOH PER GRAM OF PRODUCT THE IMPROVEMENT OF MAKING SAID BASIC ALKALINE EARTH-REACTED HYDROLYZED REACTION PRODUCT SUITABLE FOR ADMIXING WITH A POLYMERIC HIGH MOLECULAR WEIGHT UNSATURATED POLYBASIC CARBOXYLIC ACID IN THE RATIO OF FROM ABOUT 20:1 TO ABOUT 20:2 RESPECTIVELY, IN A HYDROCARBON LUBRICATING OIL WITHOUT THICKENING SAID BASIC ADMIXTURE, WHICH IMPROVEMENT COMPRISES BLOWING SAID ALKALINE EARTH-CONTAINING PHOSROUS SULFIDE-HYDROCARBON REACTION PRODUCT WITH CARBON DIOXIDE AT A TEMPERATURE OF FROM ABOUT 100* F. TO ABOUT 350*F. FOR A TIME SUFFICIENT TO REDUCE THE ALKALINITU OF SAID ALKALINE EARTH-CONTAINING PHOSPHORUS SULFIDE-HYDROCARBON REACTION PRODUCT TO A VALUE OF ABOUT ZERO MILLIGRAM NAOH PER GRAM OF PRODUCT PRIOR TO ADMIXTURE WITH SAID POLYMERIC HIGH MOLECULAR WEIGHT UNSATURATED POLYBASIC CARBOXYLIC ACID. 